// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "media/base/audio_bus.h"

#include <stddef.h>
#include <stdint.h>

#include <limits>

#include "base/logging.h"
#include "base/memory/ptr_util.h"
#include "base/numerics/safe_conversions.h"
#include "media/base/audio_parameters.h"
#include "media/base/audio_sample_types.h"
#include "media/base/limits.h"
#include "media/base/vector_math.h"

namespace media {

static bool IsAligned(void* ptr)
{
    return (reinterpret_cast<uintptr_t>(ptr) & (AudioBus::kChannelAlignment - 1)) == 0U;
}

// In order to guarantee that the memory block for each channel starts at an
// aligned address when splitting a contiguous block of memory into one block
// per channel, we may have to make these blocks larger than otherwise needed.
// We do this by allocating space for potentially more frames than requested.
// This method returns the required size for the contiguous memory block
// in bytes and outputs the adjusted number of frames via |out_aligned_frames|.
static int CalculateMemorySizeInternal(int channels,
    int frames,
    int* out_aligned_frames)
{
    // Since our internal sample format is float, we can guarantee the alignment
    // by making the number of frames an integer multiple of
    // AudioBus::kChannelAlignment / sizeof(float).
    int aligned_frames = ((frames * sizeof(float) + AudioBus::kChannelAlignment - 1) & ~(AudioBus::kChannelAlignment - 1)) / sizeof(float);

    if (out_aligned_frames)
        *out_aligned_frames = aligned_frames;

    return sizeof(float) * channels * aligned_frames;
}

static void ValidateConfig(int channels, int frames)
{
    CHECK_GT(frames, 0);
    CHECK_GT(channels, 0);
    CHECK_LE(channels, static_cast<int>(limits::kMaxChannels));
}

void AudioBus::CheckOverflow(int start_frame, int frames, int total_frames)
{
    CHECK_GE(start_frame, 0);
    CHECK_GE(frames, 0);
    CHECK_GT(total_frames, 0);
    int sum = start_frame + frames;
    CHECK_LE(sum, total_frames);
    CHECK_GE(sum, 0);
}

AudioBus::AudioBus(int channels, int frames)
    : frames_(frames)
    , can_set_channel_data_(false)
{
    ValidateConfig(channels, frames_);

    int aligned_frames = 0;
    int size = CalculateMemorySizeInternal(channels, frames, &aligned_frames);

    data_.reset(static_cast<float*>(base::AlignedAlloc(
        size, AudioBus::kChannelAlignment)));

    BuildChannelData(channels, aligned_frames, data_.get());
}

AudioBus::AudioBus(int channels, int frames, float* data)
    : frames_(frames)
    , can_set_channel_data_(false)
{
    // Since |data| may have come from an external source, ensure it's valid.
    CHECK(data);
    ValidateConfig(channels, frames_);

    int aligned_frames = 0;
    CalculateMemorySizeInternal(channels, frames, &aligned_frames);

    BuildChannelData(channels, aligned_frames, data);
}

AudioBus::AudioBus(int frames, const std::vector<float*>& channel_data)
    : channel_data_(channel_data)
    , frames_(frames)
    , can_set_channel_data_(false)
{
    ValidateConfig(
        base::checked_cast<int>(channel_data_.size()), frames_);

    // Sanity check wrapped vector for alignment and channel count.
    for (size_t i = 0; i < channel_data_.size(); ++i)
        DCHECK(IsAligned(channel_data_[i]));
}

AudioBus::AudioBus(int channels)
    : channel_data_(channels)
    , frames_(0)
    , can_set_channel_data_(true)
{
    CHECK_GT(channels, 0);
    for (size_t i = 0; i < channel_data_.size(); ++i)
        channel_data_[i] = NULL;
}

AudioBus::~AudioBus() { }

std::unique_ptr<AudioBus> AudioBus::Create(int channels, int frames)
{
    return base::WrapUnique(new AudioBus(channels, frames));
}

std::unique_ptr<AudioBus> AudioBus::Create(const AudioParameters& params)
{
    return base::WrapUnique(
        new AudioBus(params.channels(), params.frames_per_buffer()));
}

std::unique_ptr<AudioBus> AudioBus::CreateWrapper(int channels)
{
    return base::WrapUnique(new AudioBus(channels));
}

std::unique_ptr<AudioBus> AudioBus::WrapVector(
    int frames,
    const std::vector<float*>& channel_data)
{
    return base::WrapUnique(new AudioBus(frames, channel_data));
}

std::unique_ptr<AudioBus> AudioBus::WrapMemory(int channels,
    int frames,
    void* data)
{
    // |data| must be aligned by AudioBus::kChannelAlignment.
    CHECK(IsAligned(data));
    return base::WrapUnique(
        new AudioBus(channels, frames, static_cast<float*>(data)));
}

std::unique_ptr<AudioBus> AudioBus::WrapMemory(const AudioParameters& params,
    void* data)
{
    // |data| must be aligned by AudioBus::kChannelAlignment.
    CHECK(IsAligned(data));
    return base::WrapUnique(new AudioBus(params.channels(),
        params.frames_per_buffer(),
        static_cast<float*>(data)));
}

void AudioBus::SetChannelData(int channel, float* data)
{
    CHECK(can_set_channel_data_);
    CHECK(data);
    CHECK_GE(channel, 0);
    CHECK_LT(static_cast<size_t>(channel), channel_data_.size());
    DCHECK(IsAligned(data));
    channel_data_[channel] = data;
}

void AudioBus::set_frames(int frames)
{
    CHECK(can_set_channel_data_);
    ValidateConfig(static_cast<int>(channel_data_.size()), frames);
    frames_ = frames;
}

void AudioBus::ZeroFramesPartial(int start_frame, int frames)
{
    CheckOverflow(start_frame, frames, frames_);

    if (frames <= 0)
        return;

    for (size_t i = 0; i < channel_data_.size(); ++i) {
        memset(channel_data_[i] + start_frame, 0,
            frames * sizeof(*channel_data_[i]));
    }
}

void AudioBus::ZeroFrames(int frames)
{
    ZeroFramesPartial(0, frames);
}

void AudioBus::Zero()
{
    ZeroFrames(frames_);
}

bool AudioBus::AreFramesZero() const
{
    for (size_t i = 0; i < channel_data_.size(); ++i) {
        for (int j = 0; j < frames_; ++j) {
            if (channel_data_[i][j])
                return false;
        }
    }
    return true;
}

int AudioBus::CalculateMemorySize(const AudioParameters& params)
{
    return CalculateMemorySizeInternal(
        params.channels(), params.frames_per_buffer(), NULL);
}

int AudioBus::CalculateMemorySize(int channels, int frames)
{
    return CalculateMemorySizeInternal(channels, frames, NULL);
}

void AudioBus::BuildChannelData(int channels, int aligned_frames, float* data)
{
    DCHECK(IsAligned(data));
    DCHECK_EQ(channel_data_.size(), 0U);
    // Initialize |channel_data_| with pointers into |data|.
    channel_data_.reserve(channels);
    for (int i = 0; i < channels; ++i)
        channel_data_.push_back(data + i * aligned_frames);
}

// Forwards to non-deprecated version.
void AudioBus::FromInterleaved(const void* source,
    int frames,
    int bytes_per_sample)
{
    switch (bytes_per_sample) {
    case 1:
        FromInterleaved<UnsignedInt8SampleTypeTraits>(
            reinterpret_cast<const uint8_t*>(source), frames);
        break;
    case 2:
        FromInterleaved<SignedInt16SampleTypeTraits>(
            reinterpret_cast<const int16_t*>(source), frames);
        break;
    case 4:
        FromInterleaved<SignedInt32SampleTypeTraits>(
            reinterpret_cast<const int32_t*>(source), frames);
        break;
    default:
        NOTREACHED() << "Unsupported bytes per sample encountered: "
                     << bytes_per_sample;
        ZeroFrames(frames);
    }
}

// Forwards to non-deprecated version.
void AudioBus::FromInterleavedPartial(const void* source,
    int start_frame,
    int frames,
    int bytes_per_sample)
{
    switch (bytes_per_sample) {
    case 1:
        FromInterleavedPartial<UnsignedInt8SampleTypeTraits>(
            reinterpret_cast<const uint8_t*>(source), start_frame, frames);
        break;
    case 2:
        FromInterleavedPartial<SignedInt16SampleTypeTraits>(
            reinterpret_cast<const int16_t*>(source), start_frame, frames);
        break;
    case 4:
        FromInterleavedPartial<SignedInt32SampleTypeTraits>(
            reinterpret_cast<const int32_t*>(source), start_frame, frames);
        break;
    default:
        NOTREACHED() << "Unsupported bytes per sample encountered: "
                     << bytes_per_sample;
        ZeroFramesPartial(start_frame, frames);
    }
}

// Forwards to non-deprecated version.
void AudioBus::ToInterleaved(int frames,
    int bytes_per_sample,
    void* dest) const
{
    switch (bytes_per_sample) {
    case 1:
        ToInterleaved<UnsignedInt8SampleTypeTraits>(
            frames, reinterpret_cast<uint8_t*>(dest));
        break;
    case 2:
        ToInterleaved<SignedInt16SampleTypeTraits>(
            frames, reinterpret_cast<int16_t*>(dest));
        break;
    case 4:
        ToInterleaved<SignedInt32SampleTypeTraits>(
            frames, reinterpret_cast<int32_t*>(dest));
        break;
    default:
        NOTREACHED() << "Unsupported bytes per sample encountered: "
                     << bytes_per_sample;
    }
}

// Forwards to non-deprecated version.
void AudioBus::ToInterleavedPartial(int start_frame,
    int frames,
    int bytes_per_sample,
    void* dest) const
{
    switch (bytes_per_sample) {
    case 1:
        ToInterleavedPartial<UnsignedInt8SampleTypeTraits>(
            start_frame, frames, reinterpret_cast<uint8_t*>(dest));
        break;
    case 2:
        ToInterleavedPartial<SignedInt16SampleTypeTraits>(
            start_frame, frames, reinterpret_cast<int16_t*>(dest));
        break;
    case 4:
        ToInterleavedPartial<SignedInt32SampleTypeTraits>(
            start_frame, frames, reinterpret_cast<int32_t*>(dest));
        break;
    default:
        NOTREACHED() << "Unsupported bytes per sample encountered: "
                     << bytes_per_sample;
    }
}

void AudioBus::CopyTo(AudioBus* dest) const
{
    CopyPartialFramesTo(0, frames(), 0, dest);
}

void AudioBus::CopyPartialFramesTo(int source_start_frame,
    int frame_count,
    int dest_start_frame,
    AudioBus* dest) const
{
    CHECK_EQ(channels(), dest->channels());
    CHECK_LE(source_start_frame + frame_count, frames());
    CHECK_LE(dest_start_frame + frame_count, dest->frames());

    // Since we don't know if the other AudioBus is wrapped or not (and we don't
    // want to care), just copy using the public channel() accessors.
    for (int i = 0; i < channels(); ++i) {
        memcpy(dest->channel(i) + dest_start_frame,
            channel(i) + source_start_frame,
            sizeof(*channel(i)) * frame_count);
    }
}

void AudioBus::Scale(float volume)
{
    if (volume > 0 && volume != 1) {
        for (int i = 0; i < channels(); ++i)
            vector_math::FMUL(channel(i), volume, frames(), channel(i));
    } else if (volume == 0) {
        Zero();
    }
}

void AudioBus::SwapChannels(int a, int b)
{
    DCHECK(a < channels() && a >= 0);
    DCHECK(b < channels() && b >= 0);
    DCHECK_NE(a, b);
    std::swap(channel_data_[a], channel_data_[b]);
}

scoped_refptr<AudioBusRefCounted> AudioBusRefCounted::Create(
    int channels, int frames)
{
    return scoped_refptr<AudioBusRefCounted>(
        new AudioBusRefCounted(channels, frames));
}

AudioBusRefCounted::AudioBusRefCounted(int channels, int frames)
    : AudioBus(channels, frames)
{
}

AudioBusRefCounted::~AudioBusRefCounted() { }

} // namespace media
